Application of transparent polycrystalline body with high ultraviolet transmittance

A window comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said window having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A pressure vessel sight glass consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said sight glass having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A furnace sight glass consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said sight glass having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A windshield for a vehicle consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said windshield having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A UPC bar code scanning device window comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said UPC bar code scanning device window having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A waveguide comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said waveguide having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A feed-through in an optical downhole well logging sensing system comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said feed-through in an optical downhole well logging sensing system having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

An optical fiber connector comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said optical fiber connector having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A pump piston for chromatography applications comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said pump piston for chromatography applications having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A pump cylinder for chromatography applications comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said pump cylinder for chromatography applications having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A column for chromatography applications comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said column for chromatography applications having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A thermoset mold window comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said thermoset mold window having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A water-jet cutting flow-shaper comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said water-jet cutting flow-shaper having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A nozzle for process fluids comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said nozzle for process fluids having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A valve flap comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said valve flap having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A valve seat comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said valve seat having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A component in integrated-circuit imaging equipment comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said component in integrated-circuit imaging equipment having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A high-pressure arc-lamp enclosure comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said high-pressure arc-lamp enclosure having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A high-pressure arc lamp lens comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said high-pressure arc lamp lens having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A port for receiving and transmitting radiation signals comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said port for receiving and transmitting radiation signals having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A port for missile guidance and detection comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said port for missile guidance and detection having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A ball bearing comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said ball bearing having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

Components in a high speed printer comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said components in a high speed printer having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A liquid ink plotting pen comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said liquid ink plotting pen having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

An optical lens comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said optical lens having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

Components for optical computers comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said components for optical computers having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

An optical fiber comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising;

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said optical fiber having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A thermometer comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said thermometer having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

An optical fiber sensor comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said optical fiber sensor having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A flow meter comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said flow meter having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A capillary tube comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said capillary tube having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A pressure transducer comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said pressure transducer having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A wafer for electronic application comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said wafer for electronic application having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A cryogenic temperature sensor comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said cryogenic temperature sensor having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A watch crystal comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said watch crystal having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

Safety goggles comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said safety goggles having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

Cookware comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said cookware having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A rotary encoder comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said rotary encoder having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A fiber optic beam splitter comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said fiber optic beam splitter having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A covering for a submarine port comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said covering for a submarine port having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A covering for a tank port comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said covering for a tank port having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A carrier disk comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said carrier disk having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A radiation hardened RAM substrate comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said radiation hardened RAM substrate having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A trimmer capacitor comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said trimmer capacitor having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A prism comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said prism having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

Armor comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said armor having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A fuse cover comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said fuse cover having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A holographic grating comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said holographic grating having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.

A diffraction grating comprising a sintered polycrystalline body consisting essentially of magnesia-alumina spinel produced by a process comprising:

• providing a powder comprising magnesia-alumina spinel;
• producing a closed porosity body from said powder;
• and
• heating said closed porosity body to at least about 1400.degree. C. at elevated pressure of at least about 20,000 psi to reduce residual porosity;
• said diffraction grating having a transmittance per 1.88 millimeter thickness in all wavelengths from about 0.3 to about 0.8 microns of not less than about 85 percent.